1. Field of the Invention
This invention relates to a new gel product for exterminating harmful marine organisms and to a method of exterminating said organisms. According to the present invention, there is provided a novel gel product for exterminating harmful marine organisms, as well as a method of applying such product, which is particularly effective in preventing the boring of lumber by Teredos when the lumber is stored in a lumber pooling area in the sea.
2. Description of the Prior Art
Various exterminatory materials for destroying harmful marine organisms such as Teredos, Mytilus edulis, barnacles, Hydrozoa, Bryozoa, etc., are known. They have been applied, for example, by dissolving or suspending the active material in a solvent which is then added to the sea water so as to maintain a constant concentration.
In Japanese Patent Early Publication No. 12239/1975, there is disclosed that a copper or lead compound may be gelled with a hydrophilic synthetic resin such as a polyvinyl alcohol having a molecular weight of 500 to 3000, and such gel is used for exterminating starfish.
Among the harmful marine organisms, Teredo (commonly called shipworm or pileworm) belongs to the Teredinidae family, Bivalvia class, Mollusca. The Teredo has a way of life which is very different from other marine organisms (such as Mytilus edulis, barnacles, Hydrozoa, Bryozoan, etc.). The Teredo is a living organism which attaches to marine constructions, typically on the surface of lumber, and through metamorphosis bores into the lumber. It does not live by eating plankton in the sea water as its primary food, but rather relies upon cellulose in lumber as a nutritive source.
A floating larva of Teredo has the same way of life as one of the Bivalves, but it effects a different metamorphosis from the larvae of other Bivalves in the stage of metamorphosis after attaching, and cannot live without lumber of some other source of cellulose.
There are many occasions which require one to store lumber in the sea. The Teredo will often bore lumber during its sea storage, which, of course, markedly decreases the price. However, exterminatory products for destroying the Teredo have not heretofore been satisfactory in a lumber pool, because of a number of different problems depending upon the large surface of the sea, the particular kind of reagent, the method of application of the reagent, the effect of the reagent, etc.
It is very difficult to maintain a desired concentration of an effective component, when the component is diluted with solvents and added to the sea. Moreover, the description given in Japanese Patent Early Publication No. 12239/1975 does not result in a satisfactory gel product, nor does it result in an adequately effective exterminatory product.
The following considerations are desirable in order to obtain a satisfactory gel product:
(1) The effective (active) components should be dissolved in the sea; PA1 (2) the amount dissolved should reach an effective concentration in a relatively short time; PA1 (3) when the product is used in a lumber pool, the amount dissolving should be maintained at a constant rate, because the effective concentration should remain constant during the period of time which is generally required for storing lumber in sea water typically from one half to three months; PA1 (4) the product should be able to be handled easily, that is, it should hold exhibit elasticity and flexibility, and should not be sticky on its surface; PA1 (5) the product should float on the sea (when used in a lumber pool); PA1 (6) if possible, the components of the product should not be harmful. PA1 (a) about 1-25 w/w % of a natural high molecular weight compound capable of forming a gel in water, PA1 (b) about 5-30 w/w % of an agent for exterminating harmful marine organisms, PA1 (c) about 1-25 w/w % of at least one compound selected from the group consisting of a water-soluble synthetic linear polymer, an inorganic substance, a surfactant, an organic solvent, a gel-modifier, and mixtures thereof, and PA1 (d) water. PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w/ % PA1 (c) Water-soluble linear polymer, 0.5 to 5.0 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Water-soluble synthetic linear polymer, 0.5 to 5.0 w/w % Inorganic substance, 1 to 10.0 w/w % Surfactant, 0.1 to 5.0 w/w % Total of the components in (c) 1 to 25 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Water-soluble synthetic linear polymer, 0.5 to 5.0 w/w % Inorganic substance, 1.0 to 10.0 w/w % Surfactant, 0.1 to 5.0 w/w % Organic solvent, 1.0 to 20.0 w/w % Total of the components in (c), 1 to 25 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Water-soluble synthetic linear polymer, 0.5 to 5.0 w/w % Inorganic substance, 1.0 to 10.0 w/w % Surfactant, 0.1 to 5.0 w/w % Organic solvent, 1.0 to 20.0 w/w % Gel-modifier, 0.01 to 5.0 w/w % Total of the components in (c), 1 to 25 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Water-soluble synthetic linear polymer, 0.5 to 5.0 w/w % Organic solvent, 1.0 to 20.0 w/w % Total of the components in (c), 1 to 25 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Water-soluble synthetic linear polymer, 0.5 to 5.0 w/w % Inorganic substance, 1.0 to 10.0 w/w % Gel-modifier, 0.01 to 5.0 w/w % Total of the components in (c), 1 to 25 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Inorganic substance, 1.0 to 10.0 w/w % PA1 (d) the remainder--water PA1 (a) 1 to 25 w/w % PA1 (b) 5 to 30 w/w % PA1 (c) Inorganic substance, 1.0 to 10.0 w/w % Surfactant, 0.1 to 5.0 w/w % Total of the components in (c), 1 to 25 w/w % PA1 (d) the remainder--water